Joseph nason



PETERSv PHOTO-LITMOGRAPHER. WASHINGTON. D C4 JOSEPH NASON, OE NEW YORK,` N. Y;

' ARRANGEMENT FOR CUTTING scREws I'N LATHE'S.

Specification ofLetters Patent No. 10,383, dated January 3, l1854.-

Y To all whom t may concern:

Be it known that I, JOSEPH NAsoN, of the city, county, and State of New York, have invented cert-ain new and useful Improvements in Machinery and Tools for Cutting the Threads of Screws, the following being a clear and exact description thereof, reference being had to the accompanying drawing, in which- Figure l is a front elevation. Fig. 2 is a plan. Fig. 3 is a view of the head end of the lathe and attachments. Fig. 4 is an elevation showing the tool in its position for cutting exterior screws. Fig. 5 is an elevation showing the position of the tool for cutting interior screws. Fig. 6 is an elevation showing the tool thrown back out of use. Y

My improvements, although designed to facilitate the process of threading screws generally, which have their threads cut by rotation in the lathe against a sliding tool, are more especially intended to supersede the well known process of hand chasing, to which end they are made auxiliary to the vusual and requisite functions of a screw cutting lathe-such as, centering, turning and boring-and their chief novelty consists in their adaptation to, and combination with the turning lathe, so as not in any manner to interfere with or hinder the ordinary routine of manipulation, either preparatory to, or after the operation of screw cut-ting.

The construction, is as followsVThertail stock (a) and rail of the lathe (b) are like those in common use, as is also the head stock (c) with the additions about to be described. Upon the rear side of one of t-he posts of the head stock (c) is an extension or bracket (e) supporting a stud (f) which projectsoutward parallel to the axis of the mandrel (l). Fitted to the stud is a tube (g) which is turned upon it by the toothed wheel (la.) driven by thevpinion upon the mandrel. This tube receives an gives motion to the guidescrew (j) which goes over and is fastened to it oy a slotand key. A nut upon the end of the stud forms the end bearing of the tube and guide screw, and is unscrewed when the guide screw is to be removed or changed.

The two wheels (h) andv (i) should have in their number of teeth a common multiple. They are seldom or never removed and their diameters are made dissimilar only for the purpose of giving to the guide screw slide freely.

a slower rate ofv motion thant-hat of mandrel (d) whereby it maybe made of coarser pitch than that of the screw to be cut and its wear materially lessened. l

Upon the back rail of the lathe are two eyes or bearings (la 76,)l Support-ing the shaft (l) which extends the whole length of the lathe (or less) and is very accurately fit-ted to the bearings (lc k) yet solas to turn or On the head end of the shaft (Z) is fastened the guide arm which projects forward over the guide screw (j) and has at its termination a socket to hold the threaded block (a). which'engages with the thread upon the guide screw (j). The block (a) is held in the socket by a screw and is to be removed along with the guide screw to which it belongs, whenever a change of thread is required. Y V The thread on the block, should correspond exactly to that on the guidescrew. A simple vand effective mode of obtaining this correspondence is to make first a duplicate in steel of the intended guide screw and cross-groove the threads so as to form cutting teeth after the fashion of an ordinary master tap. With this cut-ter prepare a chasing tool in the usual manner. Vit-h the chasing tool cut the thread upon the guide screw-which will then be anexactV copy of the cutter. Finally, place the cutter upon thetube (g) and while it is rotating press the block (n) against `it until a thread is cut in the block of the required depth. Upon removing thecutter and re placing the guide' screw, the two threads, namelyupon the guide vscrew and block,- will fit each other perfectly.v

Upon the shaft (Z) between its bearings (7c 7c) is a tool bearer (o) which can be moved along the shaft and fastened at anyV point desired bythe screw (79)( yThe tool bearer is of triangular form as shown 1n Flgst and 6. Its lower arm extends forward across the rails when 1n its working position, and rests firmly upon the front rail The slot (ujginfthe'slide rest assists in adi or several teeth like a common chasing tool,

the latter being'in` most cases preferable."

The same tool postis employed for cutting exterior and interior threads b'y' merely `its position asl shown in Figs; V4

The toolbearer, shaft and attachments are moved `and operated by taking hold of the `handle The collar (y) whichA is movable upon the'shaft isyoccasionally `used to arrest the back'motion' of the shaft and tool 'bearerby itscontact with the bearing (7c).

A supplementary device called a .tcol lifter 'is shown in Figs.'2 and (A1),re`p resents' a block having a deepgroove which embraces and slides uponthe'` front rail of the lathe to which it maybe fastened 'at any ldesired pointJ by the Vthumb screw (b1).

Upon itsl upper side is the short inclined 'plane L(c1) ,having `an angle of `about 45 degrees. Upon the `forward extremity of the tool bearer is a sma'll roller V(dliwhich upon passingthe inclined plane lifts the tool 'bearer fromits front bearing,the block from theguide screw, and the cuttin tool from the'work. The tool lifter isv chie y employed Ywhen screws are to be cut against vshoulders or proj ection'sor when one or'more threads are to terminate abruptly.

The" operationis as followszyThe piece vto be threadedhaving been turned or bored, the tool bearer (whichduring this operation Ahasbeen thrown back in the position shown in Fig. `6) Vis brought down into the position shown in Figs; vl, 2, 4 and 5, when it rests upon the front rail of the lathe and is made Ato traverse endwise bythe guide screw (j), Vwhich now engages the block (n). The cutting tool (t) is nextbrought down to the work as shown in Figs. 4 and 5, and as it moves over the work the depth of the cut is adjusted 'by `the screw (7). Having described the thread tothe required length the tool bearer is suddenly raised high enough to disengage the'block from the guide screw 'and the tool from the'work, both of which operations it is' to be observed are made simultaneous by the connection ofthe tool bearer and block with theJshaft The tool bearer may be raised by thejhand or by the tool nlifter before described."` TheL shaft (Z) and its attachments being thus set atliberty are to be carried back by the hand to their original position, which may be deterortaken olfexpeditiously.`

ymined and Xe'd if` necessary by'fastening the collar at the "proper poi'nt upon the shaft. The tool bearer is again brought "down-to its working position, the tool advanced for a second cut, and the forward,

llifting; andbacli'motions gone throughwith as before. These operations are to be re- "peated until'the thread is `cut to the depth required. `When one or more' duplicate screws are to be threaded,`the depth ofthe cut is regulated vby ther-'gage screw (W). To lessen the labor of moving the shaft `and attachment-s through the back motion, it is `usual to employ aweight `attachediito a chain, which passing over' a pulley is connected to the back endv of the shaft. .i These parts are not'shown in the drawings.`

Having thusffully described my improve- 1nents,'l remark thatgseveralof the parts` which enter into Athe combination `herein set Vvforth having been previously known and used, I do not claim' them separately asilny invention. The slide `rest and guide `screw `1nore `especially have been ylong employed together for the purpose ofcutting `thethreads of screws.' I do nottherefore claim-.either 2. The mode of `constructing 1 the tool bearerA generally, particularly 'as regards placingv the slide rest behind the work whereby the cutting tool 1` is brought into such relative position with the shaft and the mandrel that the operation Aof raising `the tool bearer from the rail lremoves thetool from the work. i Y i f i i 3. The tool lifter constructed substantially as described and employed for the purposes, and in the manner herein specified. .i

4. The combination of the guide screwl,ithe threaded block, andthe tool bea-rer with the shaft,v substantially as set forth,by lwhich i (l) the requisite traversingV motion is iinpartedto the cuttingtool, (2) the operations of releasing the blockfrom the guide screw, and removing the tool from the `work' are sillO multaneously performed, and (i-thetool i bearer may be turned back out of the way 4when notin use. M y

' JOSEPH NASON. i Vitnesses: i

` J. J. GREENOUGH,

RICHARD WINNE.' 

